1. Technical Field
The present invention relates to, for example, an OCB-mode (optically compensated bend mode) liquid-crystal-device driving method, a liquid crystal device having an OCB mode, and an electronic apparatus including the liquid crystal device.
2. Related Art
In recent years, in the field of liquid crystal devices typified by liquid crystal television sets, etc., OCB-mode liquid crystal devices that have fast response speeds for the purpose of improving moving image quality have attracted lots of attention. In the OCB mode, in an initial state, liquid crystal molecules are in a splay alignment in which the liquid crystal molecules splay between a pair of substrates. Accordingly, at a displaying time, the liquid crystal molecules need to be in a bend alignment in which the liquid crystal molecules bend. In other words, by modulating a transmittance at the displaying time on the basis of a bending level of the bend alignment, a fact response is realized. Therefore, in the case of an OCB-mode liquid crystal device, its liquid crystal is in the splay alignment. Thus, the liquid crystal device needs a so-called “initial transition operation” that, by applying a voltage whose value is not less than a threshold value to the liquid crystal when the liquid crystal device is supplied with power, performs a transition of the alignment state of the liquid crystal from the splay alignment in the initial state to the bend alignment at the displaying time. If the initial transition is not sufficiently performed, a display defect may occur and a desired fast response may not be obtained.
Methods for performing the initial transition include a method that, by applying voltages having reverse polarities to two adjacent pixels (or wires) so that a horizontal electric field is generated therebetween, irregularity in alignment, that is, disclination, occurs in liquid crystal. As described above, by allowing the liquid crystal to be in a state in which a transition nucleus can easily be generated, a transition to the bend alignment is performed. However, when the applied voltage is approximately several voltages, approximately a time from ten and several seconds to several tens of seconds is needed to perform the initial transition operation.
Although, in this case, the time required for the initial transition operation can be reduced by applying a high voltage of approximately 20 volts, a problem occurs in that the reliability of the liquid crystal device deteriorates since application of the high voltage causes a large load on the liquid crystal device. Accordingly, an initial transition method (see, for example, JP-A-2001-33827) that reduces the initial transition time by oscillating liquid crystal with a voltage of approximately several volts applied to the liquid crystal, has been proposed. In this method, by providing a liquid crystal device with an oscillator, and driving the oscillator, a transition of the alignment state of the liquid crystal from the splay alignment to the bend alignment is performed, with a transition nucleus used as a base.
However, the above initial transition method of the related art also has a problem in that the liquid crystal device is expensive since the liquid crystal device needs to include the oscillator.